"Sensei (Ueshiba Morihei) was invited to go there and give a demonstration as part of a big martial arts tournament. There were a lot of Judo practitioners around and one of them who had watched Sensei's demonstration came and challenged him, saying that he didn't believe what he had just seen. The challenger, whom I will call Mr. N was known at that time as the rival of Masahiko Kimura. Of course, Mr. N was considerably larger than the average person and when he and Sensei faced each other, it looked just like an adult with a child.

Suddenly, Mr. N came in to grab Sensei's inside collar and, pulling him in, tried to execute a hip spring throw. That was it. Mr. N's gigantic figure buckled and he crumpled to the floor right there. As for Sensei, he was standing very quietly as if nothing had happened. The spectators were thrown into an uproar because nobody quite understood what they had just witnessed.

As it happens, Sensei had delivered a light blow with his fist to Mr. N's hip just as he stepped into Sensei's chest. The timing was absolutely perfect. From a conversation I overheard later I learned that Mr. N's hip bone was broken so severely that he would never fully recover.

This same principle can be applied in free-for-all fights as well. Discerning the opponent's movements and delivering an atemi at just the right moment will result in a very effective technique."

My gut level understanding of this is: Mr. N wanted to test his technique against something he thought was not real... he wanted to throw a fellow senior budoka with a judo hane goshi that would have no lasting effect other than most likely a strong fall from the ukemi. Something judoka do with each other every time they get on the tatami together. On the other side, Ueshiba Morihei must have viewed the "confrontation" differently because he "delivered a light blow" with the "same principle can be applied in free-for-all fights" which resulted in Mr. N's hip bone being broken so severly that he would never fully recover.

I just thought this first hand memory from Shioda would illustrate one encounter that Ueshiba Morihei had with a judo man that left a strong impression on both Shioda and Mr. N.